Evidence is building regarding the association between inadequate amounts of sleep and the risk of obesity, especially in younger children. Less is known about the relationship between change in sleep and change in weight during adolescence. The objective of this study was to examine the longitudinal relationship between change in sleep duration and change in body mass index (BMI) and percent body fat (PBF) in a cohort of adolescents. The cohort included 723 adolescents (mean age = 14.7 years at baseline) from Minnesota. Total sleep duration was assessed via self-report. BMI and PBF were objectively assessed. Covariates used in the multivariate analyses included energy intake as assessed through 24-hour recalls, activity levels as assessed by accelerometers, screen time/sedentary behavior, depression, and sociodemographic characteristics. For both males and females, average BMI and PBF increased slightly over the 2 years and average sleep duration decreased by about 30 minutes. The authors saw no statistically significant longitudinal relationships between change in total sleep and change in BMI or PBF over time in either girls or boys. The only longitudinal relationship that approached statistical significance was a positive association between sleep and PBF in females (p = .068). This research contributes to the literature as the only study to date to examine how change in sleep duration during adolescence may be related to a concomitant change in BMI and body fat. The findings of this study do not support the hypothesis that a decline in sleep duration during adolescence increases obesity risk.

We examined the association between sleep duration and BMI in young adults, and, specifically, in possible gender differences. The population-based sample included 955 young men and 1051 young women (mean age = 25.3 years, s.d. = 1.7) who participated in Project EAT-III (Eating and Activity in Teens and Young Adults)-III. In 2008-2009, study participants completed a survey, on which they reported their weight, height, and typical bed and awakening times. Gender-specific regression models estimated cross-sectional associations between sleep duration and weight status, adjusting for age, race, SES, family structure, depressive symptoms, physical activity, and sedentary and dietary behaviors. In multivariable-adjusted linear regression models, an hour increase in sleep was associated with a -0.38 (-0.70, -0.048) BMI in men. Men who slept <7 h had a 1.4 unit higher mean BMI (27.9; 95% confidence interval (CI): 26.9, 28.9) than men who slept 7-9 h/day (26.5; 95% CI: 26.1, 27.0). Prevalence estimates of overweight (BMI ≥25) and obesity (BMI ≥30) were also inversely associated with sleep duration among men. Sleep duration was not associated with BMI, overweight, or obesity in women. Among women, but not men, there was a statistically significant positive association between trouble falling or staying asleep and mean BMI. Sleep may be an important modifiable risk factor for obesity, particularly in young adult men.

BACKGROUND: The aim of this study was to promote physical activity in 6th graders by developing and testing the feasibility of an enhanced Presidential Active Lifestyle Award (PALA) program comprised of a peer leadership component and innovative exercise resource toolkit including DVDs. METHODS: A racially/ethnically diverse sample of students received the standard PALA program (2 control schools, n = 61) or enhanced PALA+Peers program (2 intervention schools, n = 87) during 2006-2007 academic year. RESULTS: Compared with the control condition, the intervention was successful in increasing moderate physical activity in all students (P = .02) and moderate and hard physical activity among girls (P = .03 and P = .04, respectively). Teachers and students reported a high level of satisfaction and receptivity with the intervention. All teachers thought the DVDs were well-received, and 87% of students reported that they would recommend the enhanced program to peers. CONCLUSION: Coupling peer leadership and DVDs that promote physical activity may be an effective way to increase youth physical activity.